首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   150167篇
  免费   31175篇
  国内免费   2388篇
耳鼻咽喉   5155篇
儿科学   5385篇
妇产科学   2367篇
基础医学   2989篇
口腔科学   1475篇
临床医学   26542篇
内科学   47389篇
皮肤病学   7424篇
神经病学   14663篇
特种医学   6355篇
外科学   40866篇
综合类   245篇
现状与发展   72篇
预防医学   6931篇
眼科学   3335篇
药学   871篇
中国医学   10篇
肿瘤学   11656篇
  2024年   684篇
  2023年   4780篇
  2022年   1175篇
  2021年   3083篇
  2020年   6014篇
  2019年   2148篇
  2018年   7371篇
  2017年   7317篇
  2016年   8391篇
  2015年   8370篇
  2014年   15450篇
  2013年   15581篇
  2012年   5425篇
  2011年   5412篇
  2010年   10309篇
  2009年   14207篇
  2008年   5721篇
  2007年   3950篇
  2006年   6410篇
  2005年   3680篇
  2004年   2951篇
  2003年   1939篇
  2002年   2025篇
  2001年   3812篇
  2000年   3006篇
  1999年   3216篇
  1998年   3635篇
  1997年   3455篇
  1996年   3353篇
  1995年   3209篇
  1994年   1936篇
  1993年   1557篇
  1992年   1384篇
  1991年   1420篇
  1990年   1065篇
  1989年   1182篇
  1988年   1024篇
  1987年   862篇
  1986年   897篇
  1985年   723篇
  1984年   555篇
  1983年   522篇
  1982年   519篇
  1981年   401篇
  1980年   362篇
  1979年   310篇
  1978年   332篇
  1977年   398篇
  1975年   279篇
  1972年   303篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
BACKGROUND Hidradenitis suppurativa (HS) is a difficult disease to treat. Surgery may be curative, but just like cancer surgery, it must be complete to effect a cure. Preoperative imaging of hidradenitis lesions is therefore of interest.
OBJECTIVE The objective was to study the ultrasound characteristics of hidradenitis and compare these to the clinical findings.
MATERIALS AND METHODS Real-time compound imaging ultrasound systems were used (Philips HDI 5000 and iU22) to visualize HS lesions in seven patients and regional controls images from eight healthy volunteers.
RESULTS Hidradenitis-related features were identified: various fluid collections, increased dermal thickness (mean±SD, 3.3±1.0 mm vs. 1.4±0.3 mm for controls) and lower echogenicity of the skin. In comparison with clinical examination, we were able to identify both subclinical lesions and subclinical extension of lesions into clinically normal looking paralesional skin. Hair follicles appeared distended.
CONCLUSION A number of HS features can be identified by ultrasound. These features include both actual lesions and possible predisposing factors such as skin thickness and hair follicle morphology. Ultrasonography can identify the true extent of lesions in HS, which may be of use in the preoperative planning.  相似文献   
63.
64.
65.
66.
67.
68.
69.
The alphavbeta6 integrin is an exclusively epithelial integrin that is highly expressed during fetal development. In adult tissue, alphavbeta6 integrin is expressed during inflammation, carcinogenesis, and in wound healing. We previously reported that alphavbeta6 integrin is highly expressed in poorly healing human wounds and its over-expression is associated with chronic wounds in a mouse model. The objective of this study was to investigate the role of alphavbeta6 integrin in compromised wound healing induced by hydrocortisone treatment or aging by using young and old mice deficient in or overexpressing the beta6 integrin subunit in the epidermis. Untreated aged beta6 integrin-deficient (beta6-/-) animals showed a significant delay in wound healing when compared to their age-matched controls or younger beta6-/- mice. The most significant delay was observed at the stages where granulation tissue deposition was occurring. Hydrocortisone treatment significantly delayed wound healing in wild-type and beta6 integrin-deficient mice in comparison with the untreated controls. However, hydrocortisone treatment in beta6 integrin overexpressing animals did not cause a significant delay in wound healing. The results of this study suggest that alphavbeta6 integrin plays an important role in wound healing in animals compromised by either age or stress mimicked by hydrocortisone.  相似文献   
70.
BACKGROUND: Several clinical scoring systems have been used to evaluate the efficacy of botulinum toxin A in the treatment of hyperkinetic wrinkles. So far very few have been investigated for their reproducibility. OBJECTIVE: The aim of this study was to investigate the reproducibility of two clinical four-point scales for lateral canthal lines (crow's feet), at rest and at maximum smile. MATERIAL AND METHODS: Based on standardized photographs, a consensus atlas depicting the different severity grades [from 0 (none) to 3 (severe)] was developed. After training based on the atlas, 49 photographs at rest and 48 at maximum smile were graded by the same group of investigators on 2 consecutive days (n=9 on Day 1; n=8 on Day 2). The scores were compared for reproducibility using kappa statistics. RESULTS: Overall, reproducibility was good for both scales. Interobserver reproducibility showed an agreement of 0.6 at rest and 0.58 at maximum smile (unweighted kappa). Intraobserver reproducibility showed an agreement between 0.47 and 0.86 at rest and between 0.62 and 0.81 at maximum smile (unweighted kappa). Using weighted kappa analysis, the agreement ranged between 0.63 and 0.91 at rest and between 0.71 and 0.85 at maximum smile. CONCLUSION: The clinical scales using scores of 0 to 3 for crow's feet, both at rest and at maximum smile, show a good inter- and intraobserver reproducibility. The use of these scores in clinical trials can be recommended.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号